Two Encrypted Diplomatic Letters Sent by Jan Chodkiewicz to Emperor Maximilian II in 1574-1575


  • Nils Kopal
  • Michelle Waldispühl



Habsburg ciphers, Maximilian II, Polish-Lithuanian election, homophonic substitution cipher, cryptanalysis, linguistic analysis


This paper presents the work on two encrypted diplomatic letters sent by the Lithuanian nobleman Jan Chodkiewicz to emperor Maximilian II in 1574 and 1575. It describes the decipherment process as well as the content and the context of the letters. Furthermore, it provides linguistic aspects of the used plaintext language. It continues our previous work on Habsburg ciphers where we analyzed and contextualized three diplomatic letters sent by Maximilian II. All presented and analyzed letters relate to the Polish-Lithuanian election in 1575, where Maximilian II, his son Ernst, and his brother Ferdinand were amongst the candidates. The deciphered German plaintexts of all five letters can be accessed via the DECODE database, a storage for historical encrypted manuscripts, which is maintained by members of the DECRYPT project.